Usually, mixing different species, creates the possibility of major issues. Some people have been able to get away with it, as anemonekeeper mentioned. However, usually, this is not the case.
Another thing to consider is the species of clownfish you want to keep. I'd not recommend keeping different species of clownfish together, as this to can result in major issues. That being said, I once saw a display tank, with the biggest carpet anemone I've ever seen. On one side of the carpet, a pair of Gold Striped Maroons, with the largest female I've ever seen. The pair of GSM regularly spawned, directly under the carpet anemone. On the other side of the carpet, a tiny pair of pink Skunk Clowns, that also spawned, on a regular basis. I was amazed that the GSM allowed this, but everyone was happy...lol.